Microplastics in RAS originate from multiple sources within the system. The main contributors are linked to materials and operational wear.
Primary sources
Microplastics can come from:
- feed and feed packaging
- biofilter media wear over time
- mechanical stress on system components
Wear on biofilter media has been observed, although it is not clear whether all systems contribute equally.
System factors
Fragmentation is influenced by:
- age and condition of materials
- hydrodynamic stress
- mixing intensity in biofilters
Older systems may have higher risk of material degradation.
Operational perspective
Microplastics are not a single-source issue.
They are a result of how the system is designed, operated and maintained.
What can be controlled
Reduction measures include:
- material selection
- limiting unnecessary mechanical stress
- monitoring wear over time
Focus is on reducing generation at the source.
Key takeaway
Microplastics are mainly generated within the system. Control depends on design, materials and operation.